As the low-molecular compounds having antibacterial and anti-tumor activities and obtained from microorganisms or plants, many compounds such as anthracycline compounds, anthraquinone compounds and mitomycin compounds have so far been reported [CRC Handbook of Antibiotic Compounds, 1981, CRC Press, U.S.A.].
In order to obtain superior antibiotics and antitumor compounds, which are always in demand, many microorganisms have been isolated from nature and examined for the productivity of antibiotics. As a result, it has been found that novel antibiotics having an anti-tumor activity are produced by culturing a microorganism isolated from the soil in Sunto-gun, Shizuoka Prefecture (hereinafter referred to as DO-88 strain) and a microorganism isolated from the soil in Mt. Rokko, Hyogo Prefecture (hereinafter referred to as DO-89 strain) in a medium. These compounds have been named DC-88A and DC-89Al, respectively.